The present invention relates generally to an apparatus for conveying and break spinning fibers. More particularly, the invention relates to an apparatus for carding and conveying fibers in the form of a relatively uniform bat to a single opening roller from which fibers can be drawn to a plurality of break spinners, each equipped with a bypass operable in the event that an end comes down on the individual spinners.
In break spinning, winding and twisting are conducted at quite distinct phases of total spinning operation. Breaks, i.e., discontinuities, are deliberately introduced to the flow of fibers. Indeed, the process may be visualized as the transfer from the supply of fibers to a yarn being twisted of individual fibers at discrete intervals of time. The creation of the breaks or discontinuities results in the existence of what is often termed an "open end" to the yarn being twisted.
As the fibers travel individually across the break, each becomes essentially sequentially attached to the open end of the yarn. Concurrently, the yarn is twisted to an essentially finished aggregate of fibers.
Theoretically, because the twisting operation is isolated from the source of fibers, twist can be developed in the yarn simply by rotating the open end. Because small objects are usually of a lesser inertia, the small open end of the yarn can be twisted at high speeds and the spinning operation conducted more efficiently.
A relatively small amount of power is needed to twist or rotate the yarn. Because the spinning is discrete from the winding operation, the yarn can be wound into larger packages and the entire operation rendered more economical.
As suggested, break spinning makes it possible to conduct spinning operations at higher speeds and in a more productive manner. The cost of doffing and winding packages of yarn can be decreased in relation to the increased size of the packages and theoretically less power per unit of production is consumed. Labor costs also become less important in relation to the cost of power and the capital required.
Although the advent of break spinning represents a significant advance over other techniques, a number of problems are presented. Much of the equipment for break spinning may involve ineffective techniques for automatically transporting the fiber through the various stages of the overall spinning operation. Some techniques may employ mechanical approaches to the transport of the fiber in which the fiber is mechanically operated upon to move it from one place to another. Other techniques involve the use of electrostatic forces to draw fiber between certain stages of the spinning operation. Neither technique appears to be fully effective in transporting the fibers. The mechanical techniques often incompletely move the fiber and thus a certain quantity of fiber may be left behind. The electrostatic technique may not provide forces of magnitude sufficient to effect complete movement of fiber from one phase of the operation to another.
In the break spinning techniques employed heretofore, a pin beater or opening roller is employed to separate a fiber mass into individual fibers. These individual fibers are thereafter conveyed to a single break spinner by complex operating members. In other words, there is an individual break spinner for each opening roller. Associated with each break spinner are various elements such as feed rollers and pedals which maintain the incoming fiber mass in proper contact with the opening roller. In other words, each break spinner requires an individual apparatus for the separation of the fibrous mass into individual fibers. Inasmuch as each spinning machine thus entails the compounding of numerous break spinners and associated apparatus for opening the fibrous mass into individual fibers, a great number of moving parts are involved. The number and complexity of the various structures entails rather greater capital expense, as well as expense in the maintenance and operation of the spinning machine.
Many of the break spinning devices of the prior art do not maintain effective control over the density of the fiber mass once the fibers are drawn from the card but prior to the spinning of the fibers into yarns. Because ineffective control is exerted over the density of the fiber mass, the operation of separating the fiber mass into individual fibers may be rendered less effective, with the result that individual yarns may vary in thickness or density. This is of course undesirable where yarns of uniform quality are required.
The density or thickness of a yarn many also vary as a result of ineffective withdrawal of individual fibers from the opening roll to feed a break spinner. This appears to be a problem with numerous of the devices of the prior art wherein aggregates of fibrers rather than individual fibers may be withdrawn from the opening roll. Alternatively, the apparatus may fail to remove any fibers at all from the opening roll during an excessive period of time. Optimally, individual fibers should be removed from the opening roll at a rate selected to provide a yarn of a particular density and/or thickness. Devices of the prior art may not be sufficiently reliable in this respect.
The uniformity of a yarn may also be affected by the degree to which the individual fibers are curled, twisted, or looped as they, individually, join the open end of the yarn. For optimal uniformity in the density and thickness of the yarn, the fibers should remain relatively straight and parallel to one another with only one end thereof initially joining the open end of the yarn.
Many devices of the prior art fail to ensure this smooth mode of movement of each fiber into the spinner and onto the open end of the yarn. These devices often permit the fibers to become curled and improperly oriented and thus cause the resulting yarns to be irregular in density and thickness.
From time to time, it may be desired to alter the quality of yarn produced by an individual spinning machine. This can be accomplished in a number of ways. One way involves a change in the flux, i.e., the flow of individual fibers to the open end of the yarn. In any case, the spinning machine must be susceptible to convenient and rapid conversion so that the cost of the change may be minimized. Additionally, the machine must be capable of effecting the change in an accurate manner so that yarn is not wasted in the initial phases of the subsequent operation. Many break spinning devices of the prior art are not susceptible to a rapid, efficient and accurate change preparatory to producing a yarn of a different quality. As a result, these devices are less versatile and effecient than may be desired.
In any break spinning apparatus, the fibers transported to the spinner must be condensed from a rather low level of flux to a substantially higher level of flux. In condensing the fibers, they become grouped together at the open end of the yarn and connected thereto as the yarn is twisted. In order to maintain a yarn of uniform density and thickness, the fibers must be smoothly condensed. Many break spinning devices of the prior art do not afford sufficiently smooth condensation, but rather bring the fibers together in a rather tangled, nonparallel manner. This results in the formation of a yarn of undesirably variable density and thickness.
The opening rollers separating a fiber mass into individual fibers preparatory to spinning these individual fibers into a yarn be thoroughly cleaned of fiber as additional fibers are introduced to the opening roller. Many of the break spinning devices of the prior art do not afford efficient and thorough removal of fibers from the opening roll. Thus the fiber many become matted to the roller or wrapped therearound at various locations along the length of the roller.
From time to time as spinning operations progress, the continuous mass of fibers may break so that an end, rather than a continuous mass, is fed toward the twister. If a mass of fibers is broken, then the spinning operation must, at least in part, be interrupted so that a new continuous mass can be fed. Certain break spinning devices of the prior art require that essentially the entire spinning machine, or at least a significant portion of the productive capacity thereof, be shut down during the rethreading of the spinner. Alternatively, though the yarn is no longer being drawn from the break spinner, fibers continue to be introduced thereto. As a result, fibers may build up in the spinner and the spinner must be cleaned before the apparatus can be rethreaded. In either case, a portion, if not the entire spinning machine, may be out of production while the spinner is rethreaded. The extent of a shutdown or the duration thereof and/or a combination of both, can combine to significantly reduce the productive capacity of a spinning machine.
The problems suggested in the preceding, while not exhaustive, are among many which tend to reduce the effectiveness and desirability of apparatus of the prior art for conveying the break spinning fibers into yarns. Other noteworthy problems may also exist; however, those presented in the discussion above should be sufficient to demonstrate that such apparatus apperaing in the prior art have not been entirely satisfactory.